Separable connections or cam locks



Oct. 1, 1957 D. I. WEISZ 2,808,297

SEPARABLE CONNECTIONS OR CAM LOCKS Filed Nov. 9, 1955 United StatesPatent SEPARABLE CONNECTIONS 0R CAM LOCKS Daniel I. Weisz, Ellwood City,Pa., assignor to Beaver- Advance Corporation, Ellwood City, Pa., acorporation of Pennsylvania Application November 9, 1955, Serial No.545,863

3 Claims. (Cl. 304-40) This invention relates to knock down scaffoldsand particularly to an improvement on the connection or cam lock shownin Patents 2,435,171 and 2,483,862 for securing the diagonal braces orstays to the spaced rectangular end frames of such scaffolds in order toform a rigid selfsustaining structure.

Knock down scaffolds are used extensively but the problem of quicklyassembling and removing them has never been completely solved. Varioustypes of connections or cam locks have been heretofore proposed forsecuring brace members to end frames but none have proven to be entirelya solution to the problems.

It is an object of the present invention to provide a positive lockingdevice for scaffolding.

Another object of this invention is to provide a separable connectionfor securing diagonal braces to the rectangular end frames of knock downscaffolding.

A further object of this invention is to provide a separable connectoror cam lock providing preferably a gusset plate on a scafiold end framehaving a keyhole opening therein, a pair of spaced retaining rings onthe brace adapted to pass on opposite sides of the gusset plate, acollar rotatable between the rings to pass into the key hole opening,operating means for rotating the collar and locking means automaticallyengageable by gravity within the key hole slot.

While certain objects and advantages of this invention have beendescribed above, other objects and advantages will become apparent froma consideration of the following description and the accompanyingdrawings in which:

Figure 1 is a partial elevation of a scafiold end frame and bracingmember according to this invention with the connector or cam lock ininsertable position.

Figure 2 is a partial elevation as in Figure 1 with the connector or camlock in locked position.

Figure 3 is a section on the line IIII of Figure 2.

Figures 4 4 and 4 are an exploded view of the parts making up theconnector shown in Figures 1 through 3 with the parts in isometricviews.

Referring to the drawings there is illustrated a rectangular end framefor a knock down scaffold having vertical posts 11 spaced apart byhorizontal "beams 12 welded together. The end frames 10 of a multiplesection scaffold are spaced apart and connected by diagonal braces 13extending from one frame to another. Gusset plates 14 are welded to theposts and beams in the corner of the frames. Keyhole slots 15 areprovided in the gusset plate 14, each slot having a restricted neck 16and an eye 17.

Each diagonal brace 13 is provided at its ends with spaced retainingrings or discs 18 connected by a shaft 19. A cylindrical collar 20having a pair of axially extending segmental lugs 21 on each side isrotatably mounted on the shaft 19. An operating handle 22 having anelongated opening 23 therein with parallel flat sides 24 adapted toengage the edges of one pair of lugs 21 is slidably fitted on one set ofsuch lugs 21. One of the discs 18 is provided with opposed recesses 25into which a latching lug 26 on the handle fits to hold the handleagainst rotation. The other pair of lugs 21 is adapted to slide throughthe restricted neck 16 of the key hole slot into the eye 17 whereturning of the handle 22 rotates them in the eye 17 and prevents theremoval of the diagonal brace 13.

The operation of these scaffolding members is believed to be apparentfrom the foregoing description; however a brief description follows: Thehandle 22 is turned 'to the horizontal position (Figure 1) with the lugs21 turned to pass through the restricted neck 16. When the collar 20passes into the eye 17, the handle 22 is turned to the vertical position(see Figures 2 and 3) thereby rotating the lugs 21 to prevent removalfrom the eye 17. When the handle 22 is turned to the vertical positionthe latching lug 26 enters one of the recesses 25 by reason of theWeight of the handle and the elongated hole 23 sliding on the lugs 21.When the handle is in this position, it cannot be accidentally turned torelease the brace from the gusset plate.

When it is' desired to release the brace the handle 22 is moved in thevertical direction and rotated to the horizontal position in which thelugs 21 are slidable through the restricted slot 16. V

While there is illustrated and described but a single embodiment of thisinvention it will be understood that it may be otherwise embodied withinthe scope of the following claims.

I claim:

1. A separable connection or cam lock for securing diagonal braces tothe rectangular end frames of a knock down scaffold, comprising a gussetplate on the end frames having a keyhole slot therein with an enlargedcircular eye and a restricted opening to the edge of the gusset plate, apair of spaced retaining rings on the end of the brace member adapted topass on opposite sides of the gusset plate and connected by a memberadapted to pass through the restricted neck of the keyhole slot, acollar rotatable between the retaining rings, a pair of arcuate lugsextending axially of the collar on opposite sides of the'connectingmember between the retaining rings, said lugs being dimensioned to enterthe restricted neck when turned in one position and held against removalwhen turned degrees from said one position, a handle having an elongatedopening therein fitted over said pair of lugs and slidable diametricallythereon, said handle engaging the lugs to rotate the collar on theconnecting member, an axially extending latching lug on the handle and acooperating recess in one of the retaining rings adapted to receive thelatching lug whereby the collar is locked against removal when thehandle is moved diametrically of the connecting member to bring thelatching lug into the recess and is released for rotation when thehandle is moved in the opposite direction on the lugs to lift thelatching lug from the recess in the retaining ring.

2. A separable connection as claimed in claim 1 wherein the collar isprovided with .a pair of arcuate lugs extending axially on'each side ofthe collar, one of said pair adapted to enter the restricted neck whenturned in one position and to be held against removal when turned 90degrees from said one position and the other pair receiving theelongated opening of the handle and engaged for rotation thereby.

3. A separable connection as .claimed in claim 1 wherein the chord ofeach arcuate lug is substantially equal to the diameter of theconnecting member between the lugs and the width of the restricted neckof the keyhole slot.

References Cited in the file of this patent UNITED STATES PATENTS1,130,470 Booth Mar. 2, 1915 2,483,862 Weisz Oct. 4, 1949 2,665,953Maroney et a1. Ian. 12, 1954

